Many of us do not give a second thought about the abundance of food we have at our disposal, much less the complex management required to produce, harvest, ship, process, package, store, transport and house that food. However, at the ground level, an agricultural system is a specialized form of ecosystem, and the agriculturalist really is an ecosystem manager. This is a tremendous task requiring understanding the biotic and abiotic components and interactions with all the variables, many of which he or she cannot control. This "agroecosystem" has all the same players and components of a natural system:
1. "Flow of energy" along a food chain
primary producers (plants - crops and "weeds")
primary consumers (whatever is eating those plants, including us)
secondary consumers (predators and./or parasites on the primary consumers
tertiary consumers (predators on the secondary consumers)
(Can you list participants in this chain in an agricultural system? Make a food web? Identify the "niche" of an organism in an agroecosystem"? Where do the pests fit in?)
2) "Cycling of nutrients" up through the component players and back to the soil ecosystem.
The difference in an agricultural system, is that most of the primary production (plant biomass) does not stay on-site as in a natural ecosystem but is "exported" to clothe and feed a growing human population. This creates a local imbalance in nutrients on the farm. Inputs such as fertilizers are purchased to make up for this loss but these inputs have to come from somewhere. Where? In addition, agricultural systems in this country have become specialized, with large acreages of monocultures. This is a recipe for pest problems, which in the past has often resulting in increased pesticide use.
Can this system be sustained, not only from an ecological sense of increasing population and decreased diversity of food plants but also from a human resource perspective? In the US, farmers are retiring and few young people are willing or able to step into their shoes. Who is going to produce our food? What kind of decisions will they be making about agricultural inputs such as fertilizers, pesticides, genetically modified organisms, and other aspects of production?
For many of us in the United States, adequate food and clothing is not currently and issue. We do not remember hunger in our lifetime. Many seem to feel that agriculture is boring, dirty or smelly, definitely not sexy and there is not much money to be made by being a farmer relative to investing in Wall Street or some other "hi-tech" livelihood. But what about when food does become scarce and expensive? These are some of the larger issues that make agriculture one of the most relevant fields of study today. Managing crop pests is an integral part of overall agro-ecosystem management and presents many scientific and social challenges. Farming also directly affects the surrounding community (and vice versa). One of the best ways to find out about farming is to talk to a farmer!